Selecting a power amplifier architecture may represent a complex task, involving a judicious compromise of various factors such as, for example, area occupation, efficiency, reliability and maximum output power.
So-called double distributed active transformers (DDAT's) have been proposed for use, for example, in millimeter-wave power amplifiers.
Despite the continued activity in that area, the need is still felt for improved solutions which may facilitate, for example:                delivering a high output power with a low-power supply, for example, by combining power from a plurality of active stages,        overcoming voltage/current constraints due, for example, to transistor breakdown issues,        reducing complexity of ultra-high frequency RF PA design, as possibly related to the electromagnetic (EM) domain, and        overcoming the limitations due to the space occupied by spiral inductors and transformers.        